Tokkai Hei 7-158711 published by the Japanese Patent Office in 1995 discloses a toroidal continuously variable transmission (toroidal CVT) for vehicles wherein the ratio of a rotation speed of an input disk relative to the rotation speed of an output disk, i.e., a speed ratio, is continuously varied by varying the gyration angles of a pair of power rollers gripped between the input disk and the output disk.
The power rollers are respectively supported by trunnions. When the trunnions are respectively displaced in an axial direction by hydraulic actuators, the gyration angles of the power rollers vary accordingly.